The packing is divided roughly into two groups (random packing and structured packing). Since the shape of random packing is a specific geometrical discrete pieces, it is randomly dumped and installed in the column. Meanwhile structured packing is regularly crimped layers of wire or metal or plastic sheets. Those sheets are composed of waved zonal laminas. Section of structured packing are stacked into the column. This invention claims the specific corrugated structured packing made of waved zonal laminas.
Liquid is charged to the upper part of such packing layers in the column and falls by gravity force, on the contrary vapor is charged from the lower parts of packing layer in the column and rises by pressure force. In this cycle mass and heat transfer between both fluids is promoted by counter current contact of both fluids on the packing layer. Liquid flows down uniformly on the packing layer as a dispersed phase, though vapor rises on the packing layer as a continuous phase. If liquid does not disperse uniformly, transfer efficiency decreases. In addition channeling, that means maldistribution of liquid flow, reduces transfer efficiency remarkably since contact of both fluids is extremely limited.
Liquid must be charged to the top of packing layer and dispersed as the liquid droplet in order to flow down uniformly. High performance liquid distributors are, of course, wanted, but they can not control the behavior of the liquid within the layer.
Performance (including shape) of the packing is the key factor that influences liquid behavior because liquid descends along the packing layer and it comes to a conclusion that packing performance definitely determines transfer efficiency of the unit. Liquid from distributor flows on the waved surface of each packing element, and inside & outside space of the element and repeats the current contact with rising vapor in the packing layer. Main path of rising gas is the inclining ditched space that is surrounded with the waved packing element. A considerable part of the vapor that rises diagonally in ditched space, intersects the crease of the elements, then moves to ditched space on the waved surface side of the adjacent element that intersects the previous direction. Vapor rises along zigzag path in the packing layer like this. Other than the above main path, vapor rises through the opening holes on the packing surface.
If passing of vapor through the opening hole can induce turbulence of liquid, mass transfer around near liquid interface will be enhanced. On that reason many existing structured packing have an opening holes on the waved surface. The role of the opening is not only to promote the mass transfer as mentioned, but also for liquid to easily enter to the back side of waved surface and to spread widely on the waved surface by detour of opening holes. That is the reason why the opening on the surface has a great effect on liquid flow pattern.